openproject/frontend/app/components/wp-relations/wp-relations-create/wp-relations-autocomplete/wp-relations-autocomplete.template.html

<form name="add_relation_form" class="form">
  <input type="text"
         class="wp-relations--autocomplete ui-autocomplete--input"
         ng-class="{ '-error': noResults }"
         placeholder="{{ ::text.placeholder }}">
</form>